Light speed travel.

[styley]

Say I was to get on a space ship capable of travelling twice the speed of light. I head off into space at the speed of light for two years. Then I turn and head back to earth at twice the speed of light. Would I pass myself on the way back and would only the three years have elapsed on earth when I got home?

[Bazile]

What is space time ?

[Bazile]

How can we say that nothing can travel faster than the speed of light .
Shouldn't we be saying we dont yet know of anything that can travel faster than the speed of light ?

[fo3nix]

The current theories say that nothing can start at a speed less than that of light and then increase to exceed it (in vacuum, I'm talking).

Of course you're right though, the theories may be incorrect.

For many years, the speed of light was thought to be infinite.

spacetime is the spatial dimensions, plus the temporal dimension. It's a general concept but is used in general relativity a lot. It's what matter travels 'on'.

[styley]

I'd like you, fo3nix, to go and pick holes in Einstein's works please.

[fo3nix]

I don't know enough to do that. But from what I understand, it's very complete as is. Though, I think it'll need some modifying at basic levels to quantise it, but that's another story.